Battery-depolarizer.



M. E. HOLMES.

BATTERY DEPOLARIZER.

APPLICATION FILED DEC. 13, 1913.

1,21 8,772. Patented Mar. 13, 1917.

9 WITNESSES: INI/E/VTOR MAJOR E.HIJL.ME5 W BY A TTOR/VEY UNITED STATES PATENT OFFICE.

MAJOR E. HOLMES, or LAKEWOOD, OHIO, AssIeNoR To NATIoNALoAnBoN COMPANY, or CLEVELAND, OHIO, A CORPORATION on NEW ERSEY.

BATTERY-DEPOLABIZER.

Specification of Letters Patent.

AppIieation filed December 13, 1913. Serial N 0. 806,356.

To all whom it may concern:

Be it known that I, MAJOR E. HOLMES, a citizen of the United States, residing at Lakewood, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Battery-Depolarizers, of which the following is a full, clear, and exact description.

This invention relates to the preparation of battery depolarizers and more particularly to manganese compounds for such use in dry cells. Most dry cells use manganese depolarizers in the form of the natural oxid MnO which is commonly known as pyrolusite. The natural manganese peroxid is not, however, obtained in a pure state and does not form a perfectly satisfactory depolarizer. This is due partially to its low peroxid content, but principally to the difficulty with which the oxygen is given off, and to the impurities, which not only decrease the available oxygen but are actually harmful to the depolarizing action. To prevent these difliculties various artificially prepared manganese compounds have been proposed. Most of these artificial depolarizers are more or less satisfactory because the impurities have some depolarizing value, but the chemicals required for their preparation are so expensive that it is impracticable to use the product in a dry cell, except in some instances in the so-called midget cell. In such cells an expensive depolarizer may be used because the quantity required is very small and the best materials are necessary to secure a serviceable battery built up in such a limited space. The cost, however, prevents its use in the larger sizes of dry cells.

One of they objects of my invention is to prepare an artificial battery depolarizer of increased depolarizing efiiciency.

Another object is to decrease the cost of production of an artificial depolarizer, by using cheap materials and by utilizing the materials formed in the reaction of the process.

Additional objects 'will appear 1n t he specification and drawing, in which;

The single figure is a diagrammatlc v1ew ofa form of apparatus for carrying out i the process.

It will be understood, however, that the apparatus shown in the drawing is not the .only form which could be used and the broader aspect of the invention will be particularly. set forth in the claims. In In Patented Mar. 13, 1917 co-pending application, Serial No. 794,360,

filed October 10, 1913, I have referred to a process of making colloidal manganese peroxid in which the method is somewhat similar to the process herein described. This I process 1s also suitable for the manufacperforated iron sheets are fastened within the receptacle between the top and bottom so as to form three chambers 4, 5 and 6. The chambers 4 and 5 are located between the walls of the receptacle 2 and each of the cathode plates 3, and the chamber 6 is located between the two cathode plates The top and bottom openings of the receptacle are closed by means of a suitable insulating cover 7 and base 8. Inside the cathodes 3 is placed a diaphragm 9 of woven asbestos cloth having the pores filled for example with iron .oxid, asbestos fiber and colloidal iron hydroxid. Through the cover 7, an anode 10 of graphite is inserted in the chamber 6. In the top of the cover 7, an opening 11 controlled bya valve 12 is provided for the admission of salt solution. A funnel or reservoir 13 may be used for the addition of the solution to be electrolyzed, and an opening 14 is left in the cover for the removal of the chlorin formed. The electrolyte, namely, sodium or other chlorid solution, is admitted to the chamber 6 through the opening 11 and slowly permeates through the diaphragm 9. The exterior chambers 4 and 5 have openings 15 for removing, and collecting apparatus 15 for saving, the hydrogen gas formed by the reaction. These chambers 4: and 5 contain kerosene which takes no part in the reaction and serves for settling the heavier sodium hydroxid formed. At the bottom of the chambers 4: and 5, depending channels or grooves 16 are arranged with outlet pipes 17 for the removal of the sodium hydroxid which percolates through the diaphragm. Since chlorin and sodium hydroxid are two of the chemicals used, manganous chlorid being the other, the use of such a cell is obviously very advantageous in my process.

Below the electrolytic cell is a reservoir 17 for collection of the sodium hydroxid which is removed therefrom as desired at the base through an outlet 18 controlled by a valve 19. A reaction chamber 20 into which the chemicals for producing the reaction are admitted is arranged below the receptacle 17. Another receptacle 21 having a controlling-valve 22 contains the manganous chlorid used for the reaction and is also conveniently located above the reaction chamber.

Chlorin formed during the electrolysis in the cell is conducted through a pipe 23 from the electrolytic cell into the reaction chamber 20. To facilitate the circulation of the gas, a fan or other device 24 may be inserted in the pipe and a controlling valve 25 may also be used to control the flow of gas.

The material formed bv the interaction of chemicals in the reaction chamber is removed at the bottom through a pipe 2% and valve 25 and conveniently collected in a settling chamber 26. The supernatant liquid may be removed from the chamber by means of a tube 27 and returned to the electrolytic cell to be electrolyzed again. To raise the supernatant liquid to the electrolytic cell 1", a pump 28 may be used and a valve 29 will regulate the removal. The supernatant liquid may also be removed from the settling chamber, through a pipe 30 having a valve 31 in its circuit, by means of the pump 28 already mentioned. It may then be conducted into the electrolytic cell through the pipe 32.

When a source of E. M. F. is applied to the terminals of the electrolytic cell containingthe electrolyte of salt solution, chlorin will be formed at the graphite anode 10 and collect in the chamber'6. The sodium ion traveling toward the cathode will react, upon being discharged, with the water present in the salt solution, to form sodium hydroxid and at the same time liberate hydrogen. The sodium hydroxid together with the salt solution which percolates through the diaphragm will settle in the grooves 16 of the chambers i and 5, because it is considerably heavier than the kerosene in the chambers. The hydrogen will be removed through the vents 15 and be collected in the reservoir 15. The action of the electrolytic cell need not be further described as it is old and well known in the art, but its use in connection with this process is especially advantageous because the products are so particularly suitable that the entire process is rendered very economical.

The sodium hydroxid solution collecting in the grooves 16 containing in addition considerable salt in solution is Withdrawn into the receptacle 1'?" as it is formed and later admitted as required into the reaction chamber 20 containing manganous chlorid, which is withdrawn from the reservoir 21 by opening the valve 22. Since manganous chlorid is one of the least expensive salts of manganese its utilization is a further step toward obtaining an inexpensive product. Into this solution, containing manganous chlorid, sodium chlorid and sodium hydroxid, the chlorin gas generated in the electrolytic cell is passed contimiouslv through the pipe 23 by fan 24. In order to thoroughly submit the mixture to the gas it is necessary to stir or shake the solutions tl'ioroughly. F or this purpose a stirring device 33 driven by a pulley 3i and belt 35 may be used advantageously. Sodium hydroxid is conducted either continuously or from time to time into the reaction chamber in such quantities as to keep the mixture in the reaction chamber approximately neutral in reaction. If the mixture is maintained strongly alkaline, colloidal material will be formed as set forth in the co-pending application referred to.

The reaction between the NaOH and MnCl forms manganous hydroxid which is then oxidized to a manganic compound, such as an oxid or manganite by the action of the chlorin. The oxidizing action of chlorin is due to the formation of hydrochloric acid and nascent oxygen when the chlorin gas reacts on "the Water present. The sodium by droxid present will unite with the hydrochloric acid mentioned to form sodium chlorid. This salt, as well as that present in the hydroxid solution. does not enter into the reaction, occurring in the chamber 20. In forming the manganic compound from the manganous hydroxid many intermediate compounds are formed before the Mn(OH) is completely oxidized, so that no equation would express the reaction completely.

From the above reaction it will be evident that sodium. chlorid is reformed substantially equivalent to the amount consumed because the sodium hydroxid combines with the MnCl and l-lCl to form this salt. As the depolarizer is precipitated. the

action chamber for a considerable time. The

, solution must also be stirred or shaken oction 0 casionally in order to subject all of the mixture to the action of the chlorin. From 3 to 6 hours has been found to be necessary to obtain a good product under these conditions. During this time the sodium hydroxid'is added from time to time so as to keep the mixture approximately neutral and thus neutralize the hydrochloric acid formed which would tend to dissolve the manganese oxids if the solution became strongly acid. By the use of a strongly alkaline solution, I obtain more or less colloidal manganese peroxid intermixed with the crystalloidal -form and my invention is intended to include the manufacture of such material by this process. All of the manganous chlorid is preferably introduced into the reaction chamber at the same time, but if desired may be added from time to time. After the reaction is complete, the solution and precipitate are removed to the settling chamber and the supernatant liquid may "be returned to the electrolytic cell as previously described.

The quantity of sodium hydroxid required for the reaction is considerably more than would be expected 'because much of it is consumed in preventing the solution becoming too strongly acid on account of the hydrochloric acid formed as an intermediate product. Considerable chlorin is formed in excess of the amount required for the reaction. This escapes through the liquid and may be saved by conducting through a pipe 36 into collector 37. This chlorin may be utilized in any manner, as for instance, to make bleaching powder by passing the gas through calcium oxid or to make depolarizer by passing the gas through a-mixture of solutions of a manganous salt and calcium hydroxid or other hydroxids.

It will be understood that although the sodium hydroxid and chlorin required for the reaction are preferabl formed in the electrolytic cell that this need not necessarily be the case as these materials may be obtained irsother ways. The broad feature of the invention is the use of chlorin gas to recipitate a depolarizer from a soluf a salt of manganese. By such precipitation a very eflicient depolarizer is ob tained which has a high oxygen content which is readily given off when used in a dry cell. Its specific gravity and cheapness also satisfy all requirements for a good depolarizing material.

The composition of the material will vary somewhat depending upon certain conditions such as the length of time the solutions are submitted to the action of the chlorin gas.

If the supernatant liquid is not to be used again in the electrolytic cell, other manganese salts may be used such as MnSO for instance.

Having described my invention, what I claim is: v

l. The method of making a battery depolarizer which consists of precipitating a manganous hydroxid from a manganous compound and oxidizing the hydroxid with chlorin.

2. The method of making a battery depolarizer which consists in precipitating a manganous hydroxid from a solution of manganous chlorid by means of a hydroxid and oxidizing it with chlorin.

3. The method of making a battery depolarizer Which consists in precipitating a manganous hydroxid from a solution of a manganous salt, gradually admitting chlorin to oxidize the manganous hydroxid and I simultaneously admitting a hydroxid to neutralize the acid formed by the said oxidation.

4. The method of making a battery depolarizer which consists in electrolyzing a chlorid to form a hydroxid and chlorin gas, and treating a manganese compound with the hydroxid and the chlorin.

5. The method of making a battery depolarizer which consists in formmg a hydroxid and chlorin gas by electrolysis of a 7. The method of making a battery depolarizer which consists in electrolyzing a chlorid solution to form a hydroxid and chlorin gas, admitting the hydroxid to a solution of a manganous salt to precipitate a manganous hydroxid, admitting the chlorin to the mixture to oxidize the manganous hydroxid to a manganic compound, and adding more hydroxid from time to time to neutralize the hydrochloric acid formed by the said oxidation.

In testimony whereof, I hereunto afiix my signature in the presence of witnesses.

MAJOR E. HOLMES. Witnesses:

IRA J. ADAMS, H. G. GROVER. 

